Item 8.01. Other Events. On August 6, 2026, Solid Biosciences Inc. (the “ Company”) filed a prospectus supplement (the “ Prospectus Supplement”) under the Company’s universal shelf registration statement on FormS-3(FileNo. 333-287325)that was originally filed with the Securities and Exchange Commission (the “ SEC”) on May 15, 2025 and was declared effective by the SEC on May 27, 2025 (the “ Registration Statement”), relating to the offer and sale of a total of up to $200.0 million of shares of the Company’s common stock, par value $0.001 per share (the “ Shares”), pursuant to an Amended and Restated Sales Agreement, dated March 13, 2024, with Jefferies LLC (the “ Sales Agreement”). The Company had filed a prior prospectus supplement to the Company’s universal shelf registration statement on FormS-3(FileNo. 333-277871)with the SEC on May 15, 2025 (the “ Prior Prospectus Supplement”) relating to the offer and sale of shares of the Company’s common stock having an aggregate offering price of up to $85.0 million pursuant to the Sales Agreement. As of the date of the Prospectus Supplement, the Company had issued and sold shares of common stock for aggregate gross sale proceeds of approximately $85.0 million pursuant to the Sales Agreement and the Prior Prospectus Supplement. Upon the filing of the Prospectus Supplement, the Company will not make any offers or sales of its common stock pursuant to the Prior Prospectus Supplement.

Item 9.01. Financial Statements and Exhibits. (d) Exhibits: